Where did you read this ? Benazir Bhutto in person denies that her government supported the Taliban or aided them. But that does not mean that the ISI did not.
Just look at the independence and insouciance that the ISI displayed over the Daniel Pearl kidnapping.
As I said, you need to read Yosef Bodansky’s books, especially his biography of Bin Laden. Bodansky is a middle east expert who was the former Director of the Congressional Task Force on Terrorism and Unconventional Warfare. Yes, I agree that Bhutto always puts on a pro-Western face when she gives interviews in the West, but when in Pakistan she is has been very pro-militant Islam. Bodansky documents this in his books.